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A273727
Numbers k such that 3k - 1 divides 3^k - 1 and 3 does not divide k.
1
1, 175952, 348880, 649078, 951625, 1495472, 1944320, 3140852, 3483200, 3643270, 4359040, 4703776, 6513584, 8170904, 9854200, 11005568, 11831890, 12149872, 12828200, 12910928, 18095630, 18964400, 22034516, 43599424, 62849024, 66322480, 82159588, 85181600
OFFSET
1,2
MATHEMATICA
Select[Range[10^6], Mod[#, 3] > 0 && PowerMod[3, #, 3*#-1] == 1 &] (* Giovanni Resta, May 29 2016 *)
PROG
(PARI) is(n)=n%3 && Mod(3, 3*n-1)^n==1 \\ Charles R Greathouse IV, May 29 2016
CROSSREFS
Cf. A233415. Subsequence of A273614.
Sequence in context: A092012 A224650 A262822 * A368419 A203406 A280447
KEYWORD
nonn
AUTHOR
STATUS
approved